Traditional pre-stressed concrete hollow-core planks are used in the construction of buildings and bridges. While concrete-based construction members are strong and low cost, they are also heavy, expensive to transport and have a high associated environmental cost.
Timber has many advantages over concrete; it has higher strength to weight, is a renewable resource, and wood-based members generally perform better during seismic events due to their reduced mass. Timber is often considered more aesthetically pleasing than concrete and therefore is less likely to necessitate painting or cladding. Despite these advantages, engineered timber structural members are used less often than concrete in large commercial building. This is due to the higher cost of timber and because the on-site construction process is often more complex than for concrete members.
Concrete construction members are available as pre-fabricated and pre-stressed lengths, whereas timber members normally require post-tensioning on site. That requires special skills and equipment and slows construction time.
In this specification where reference has been made to patent specifications, other external documents, or other sources of information, this is generally for the purpose of providing a context for discussing the features of the invention. Unless specifically stated otherwise, reference to such external documents or such sources of information is not to be construed as an admission that such documents or such sources of information, in any jurisdiction, are prior art or form part of the common general knowledge in the art.
It is an object of at least preferred embodiments of the present invention to provide a pre-stressed beam or panel, and a method for manufacturing a pre-stressed beam or panel that addresses the above mentioned problems and/or that at least provides the public with a useful alternative.